This application is for the establishment of a University of Alabama at Birmingham (UAB) Digestive Diseases Research Development Center (DDRDC), focusing on the interaction between microbes and the host in mucosal tissues. Principal among the microbes to be studied will be HIV-1, which enters the host through the gastrointestinal and genital tract mucosae; Helicobacter pylori, the most common cause of gastric inflammatory disease; and the commensal bacterial flora, which plays a critical role in the pathogenesis of inflammatory bowel disease. UAB's mucosal immunologists, recognized for their leadership in the study of mucosal pathogens and mucosal ceil immunobiology, have heretofore collaborated individually in an informal, project-oriented manner. We believe that a DDRDC will synergize the research efforts of these investigators into a world-class, program-oriented, mucosal immunology research group more capable of accomplishing breakthroughs in digestive diseases research. Accordingly, the goals for a DDRDC at UAB are the following: (1) Provide an efficient and effective mechanism for expediting, expanding and fostering research in the interaction between microbes, especially HIV-t, H. pylori and the commensal flora, mucoal [sic] epithelium and mucosal innate and adaptive immune cells. (2) Coordinate and pool University-wide resources otherwise not available to individual UAB mucosal immunoogists [sic] in a cost-effective, user-friendly Center. (3) Provide a resource-, expertise- and intellectual-rich environment to generate new concepts in mucosal HIV-1, H. pylori and commensal microbe immunobiology, resulting in new initiatives inte [sic] and investigators in digestive diseases research. These goals will be accomplished through three Cores, including a (1) Genetically-Defined [sic] Microbe and Expression Core, (2) Cell and Molecular Pathology Core, and (3) Gnotobiotic and Genetically-Engineered [sic] Mouse Core. These Cores will promote digestive disease research at UAB and enhance the goals of the DDRDC program. Since the space and equipment for each Core are largely in place, this application seeks funding to staff, supply and run the Cores. In summary, the goals and components described above define the proposed UAB DDRDC.